fix: do not list delete-marked objects (#13864)

delete marked objects should not be considered
for listing when listing is delimited, this issue
as introduced in PR #13804 which was mainly to
address listing of directories in listing when
delimited.

This PR fixes this properly and adds tests to
ensure that we behave in accordance with how
an S3 API behaves for ListObjects() without
versions.

cmd/erasure-server-pool.go

@@ -1118,15 +1118,12 @@ func (z *erasureServerPools) ListObjects(ctx context.Context, bucket, prefix, ma
 	}
 
 	opts := listPathOptions{
-		Bucket:    bucket,
-		Prefix:    prefix,
-		Separator: delimiter,
-		Limit:     maxKeysPlusOne(maxKeys, marker != ""),
-		Marker:    marker,
-		// When delimiter is set make sure to include delete markers
-		// necessary to capture proper CommonPrefixes as expected
-		// in the response as per AWS S3.
-		InclDeleted: delimiter != "",
+		Bucket:      bucket,
+		Prefix:      prefix,
+		Separator:   delimiter,
+		Limit:       maxKeysPlusOne(maxKeys, marker != ""),
+		Marker:      marker,
+		InclDeleted: false,
 		AskDisks:    globalAPIConfig.getListQuorum(),
 	}
 	merged, err := z.listPath(ctx, &opts)

cmd/metacache-entries.go

@@ -53,6 +53,11 @@ func (e metaCacheEntry) isObject() bool {
 	return len(e.metadata) > 0
 }
 
+// isObjectDir returns if the entry is representing an object__XL_DIR__
+func (e metaCacheEntry) isObjectDir() bool {
+	return len(e.metadata) > 0 && strings.HasSuffix(e.name, slashSeparator)
+}
+
 // hasPrefix returns whether an entry has a specific prefix
 func (e metaCacheEntry) hasPrefix(s string) bool {
 	return strings.HasPrefix(e.name, s)

cmd/metacache-set.go

@@ -156,7 +156,7 @@ func (o *listPathOptions) gatherResults(ctx context.Context, in <-chan metaCache
 				resCh = nil
 				continue
 			}
-			if !o.IncludeDirectories && entry.isDir() {
+			if !o.IncludeDirectories && (entry.isDir() || (entry.isObjectDir() && entry.isLatestDeletemarker())) {
 				continue
 			}
 			if o.Marker != "" && entry.name < o.Marker {
@@ -168,7 +168,7 @@ func (o *listPathOptions) gatherResults(ctx context.Context, in <-chan metaCache
 			if !o.Recursive && !entry.isInDir(o.Prefix, o.Separator) {
 				continue
 			}
-			if !o.InclDeleted && entry.isObject() && entry.isLatestDeletemarker() {
+			if !o.InclDeleted && entry.isObject() && entry.isLatestDeletemarker() && !entry.isObjectDir() {
 				continue
 			}
 			if o.Limit > 0 && results.len() >= o.Limit {
@@ -324,13 +324,13 @@ func (r *metacacheReader) filter(o listPathOptions) (entries metaCacheEntriesSor
 				pastPrefix = true
 				return false
 			}
-			if !o.IncludeDirectories && entry.isDir() {
+			if !o.IncludeDirectories && (entry.isDir() || (entry.isObjectDir() && entry.isLatestDeletemarker())) {
 				return true
 			}
 			if !entry.isInDir(o.Prefix, o.Separator) {
 				return true
 			}
-			if !o.InclDeleted && entry.isObject() && entry.isLatestDeletemarker() {
+			if !o.InclDeleted && entry.isObject() && entry.isLatestDeletemarker() && !entry.isObjectDir() {
 				return entries.len() < o.Limit
 			}
 			entries.o = append(entries.o, entry)

cmd/metacache-stream.go

@@ -528,10 +528,10 @@ func (r *metacacheReader) readN(n int, inclDeleted, inclDirs bool, prefix string
 			metaDataPoolPut(meta.metadata)
 			meta.metadata = nil
 		}
-		if !inclDirs && meta.isDir() {
+		if !inclDirs && (meta.isDir() || (meta.isObjectDir() && meta.isLatestDeletemarker())) {
 			continue
 		}
-		if !inclDeleted && meta.isLatestDeletemarker() {
+		if !inclDeleted && meta.isLatestDeletemarker() && meta.isObject() && !meta.isObjectDir() {
 			continue
 		}
 		res = append(res, meta)

cmd/object-api-listobjects_test.go

@@ -42,6 +42,8 @@ func testListObjectsVersionedFolders(obj ObjectLayer, instanceType string, t1 Te
 	testBuckets := []string{
 		// This bucket is used for testing ListObject operations.
 		"test-bucket-folders",
+		// This bucket has file delete marker.
+		"test-bucket-files",
 	}
 	for _, bucket := range testBuckets {
 		err := obj.MakeBucketWithLocation(context.Background(), bucket, BucketOptions{
@@ -62,6 +64,7 @@ func testListObjectsVersionedFolders(obj ObjectLayer, instanceType string, t1 Te
 	}{
 		{testBuckets[0], "unique/folder/", "", nil, true},
 		{testBuckets[0], "unique/folder/1.txt", "content", nil, false},
+		{testBuckets[1], "unique/folder/1.txt", "content", nil, true},
 	}
 	for _, object := range testObjects {
 		md5Bytes := md5.Sum([]byte(object.content))
@@ -102,6 +105,10 @@ func testListObjectsVersionedFolders(obj ObjectLayer, instanceType string, t1 Te
 				{Name: "unique/folder/1.txt"},
 			},
 		},
+		{
+			IsTruncated: false,
+			Objects:     []ObjectInfo{},
+		},
 	}
 
 	testCases := []struct {
@@ -120,6 +127,7 @@ func testListObjectsVersionedFolders(obj ObjectLayer, instanceType string, t1 Te
 		{testBuckets[0], "unique/", "", "/", 1000, resultCases[0], nil, true},
 		{testBuckets[0], "unique/folder", "", "/", 1000, resultCases[0], nil, true},
 		{testBuckets[0], "unique/", "", "", 1000, resultCases[1], nil, true},
+		{testBuckets[1], "unique/folder/", "", "/", 1000, resultCases[2], nil, true},
 	}
 
 	for i, testCase := range testCases {